Planet Y is the latest in a series of hypothetical solar system planets that scientists have proposed in recent years, all with slightly different characteristics but collectively believed to be ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. An illustration of confirmed dwarf planets and their moons. From left to right: Pluto (with ...